Looking through the list, it's easy to figure out what Google needs to avoid when it makes decisions about acquisitions: side projects that aren't relevant to its business. If Google can't resist buying one of those companies -- and with Google, it feels inevitable that it can't -- then it needs to figure out how to let the founders build their company within Google. In two instances--Dodgeball and Jaiku--Google bought companies that could have become Twitter. Neither one is still alive.

Schmidt says most of Google's coming acquisitions will be small companies. That's good. Our review shows Google is good at is acqui-hiring smart people and plugging them into one of Google's growing products like video, or mobile.

Dodgeball

Marks: Dodgeball was an early, and pretty inexpensive, acquisition. It was a precursor of sorts to Twitter, but withered at Google. It was closed in January of this year because it made no money.

The founders of Dodgeball now run Foursquare, a mobile social network, which has 60,000 users and just raised a $1.35 million round at a $6 million valuation. The service also got a nice write up in the NYT.

Android

Grade: B

Marks: Eric Schmidt recently told reporters, "One day Larry and Sergey bought Android, and I didn’t even notice." He notices now. Schmidt says Android is ready to explode, and Verizon is running ads promoting its Droid phone in heavy rotation.

As good as all that sounds, it's hard to measure the business success of Android. The goal is to get more people on the mobile web, then make money off all the mobile searches. The question is whether those searches will be in addition to the desktop, or at the expense of? With they be as valuable, or less so? And finally, did Google really need to speed the process along? Couldn't it just let another company grow the mobile web, then reap the rewards? Maybe in a year this is an A++. For now it's a B.

YouTube: Price $1.65 Billion

Grade: A -

Marks: When Google purchase YouTube for $1.65 billion in October of 2006, the number was mind boggling. YouTube was facing a slew of lawsuits and few viable options for making money. Since then, the lawsuits have calmed down, and while monetization is still foggy, the company says it's on its way to profitability.

Why the high grade? Google has tons of cash just sitting around, so $1.65 billion isn't too bad for them. This is the number one video site on the web by miles. If you're going to acquire, acquire the best. Building a YouTube killer would cost more, and probably flop.

FeedBurner: $100 Million

Grade: D

Marks: We called FeedBurner "Google's Biggest Screw-Up To Date" last year. This was Google's easiest entry into the 'real-time' web and it was the worst. It actually slows down the web. The ad-rates are a joke, stats are still primative, and it's still wanting for new features.

On the flip side, though, Google paid very little, and it owns the RSS advertising market, though that is still tiny.

GrandCentral: $45 Million

Grade: B

Marks: It took 20 months, but Google finally turned its purchase of GrandCentral into Google Voice this Spring. The VoIP service will route all your calls to one number, and allow outgoing calls from the Internet. It could eventually challenge Skype, but that's far away.

We're giving it a B, because the company says the fees it makes on international calls are enough to pay for the service. Paying $45 million for a business that can pay its own way, and has promise down the road seems reasonable enough to us.

Pyra Labs (Blogger)

Grade: B

Marks: Blogger is huge. Just a year ago the network of blogs was pulling in 190 million uniques on a monthly basis, which Fred Wilson pointed out means 20% of all web users saw some sort of Google blog. With all those pageviews served up it "makes money" according to departed founder Ev Williams.

There's only two reasons we don't like this deal. Speaking from our own experience, Blogger is the worst of all the free blog platforms we've used. Tumblr and Wordpress are much better.

The other reason--It brought the company Ev Williams, and he slipped out of Google's grasp. He went onto oversee Odeo, then bring Twitter into the world.

Applied Semantics: $102 Million

Grade: A+

Marks: This is where the AdSense program came from. This statement from Google's Q3 earnings release pretty much says it all: "Google's partner sites generated revenues, through AdSense programs, of $1.80 billion, or 30% of total revenues, in the third quarter of 2009. This represents a 7% increase from third quarter 2008 network revenues of $1.68 billion."

Where 2 Technologies

Grade: A

Marks: This was the software company that served as a basis for Google Maps, the best maps on the web. Maps isn't a cash cow now, but it will be very important part of Google's mobile future.

Speaking from our own experience with the iPhone, we use Maps many times a day, often for searches like "bars" or "pizza." If the mobile web will be monetized how people have always dreamed, Google Maps will be a lucrative entry point for Google.

Besides that, the founders of Where 2, Lars and Jens Rasmussen are the brains behind Google Wave, which has the world atwitter with excitement.

GreenBorder

Grade: B

Marks: GreenBorder was an anti-malware, anti-spyware software company. Google picked it up mostly because it was "impressed by their small, talented team of engineers." The technology later turned up in the Chrome browser.

This is a tough one to grade, because we have no idea if they squandered an opportunity, or exploited one. We like it because we think this is the type of purchase Google will make in the next year. Pick up a small company with really smart people who will help develop Google's products.

Postini: $625 Million

Grade: A

Marks: Google is dedicated to its email, and Apps platform. Investing in a company that specializes in anti-spam/anti-virus software was a no-brainer, especially if it wants to compete with Microsoft in the enterprise market.

Jaiku

Grade: F

Marks: Google probably paid a pittance for this Twitter rival when it bought in October 2007. But, it was never developed further, and it's all but dead. The service never made Google any money, and again it was another opportunity to diffuse Twitter that Google let slip.

AdScape: $23 Million

Grade: D

Marks: This looks like one of those distracted purchases. Sure it was for a small sum, but it really didn't pay off.

Adscape provided in-game ads. At the time of the pick up, TechCrunch speculated Google was thinking of building a virtual world, and this would be useful for that. Google does have Sketchup, but Adscape didn't set the world on fire, and Google's gaming ads are immaterial.

Here's the full list

We've just graded a few of the companies Google acquired. There's many more. Here's the full list, according to Wikipedia. Grade them yourself in the comments.